Knowledge and management of specific disorders and diseases Flashcards
Define TIA.
Sudden focal neuro deficits that resolve within 24 hrs, no residual deficits, usually last 15 min
Describe the basic pathophysiology of a TIA.
Ischemia… followed by natural breakdown of blockage or collateral blood flow:
i. Atherosclerosis (enlarged atheroma most common cause) or small vessel dz (DM/HTN)
ii. Embolus
iii. Vasculitis
Describe the clinical presentation of a TIA arising from the:
- Carotid a.
- MCA
- PCA
- Basilar a./SCA/AICA
- Vertebral a./PICA
- Carotid a.–amaurosis fugax (transient monocular blindness) via ophthalmic a.
- MCA–transient hemiparesis, aphasias
- PCA–transient homonymous hemianopsia
- Basilar a./SCA/AICA–dizziness, dysphagia, dysarthria, diplopia, cerebellar ataxia
- Vertebral a./PICA–cerebellar ataxia, +/- medullary syndrome
What is the w/u for TIA?
MRI/MRA brain, carotid doppler, TTE/TEE, check glucose and BP control, if no yield–vasculitis autoimmune serum panel and LP for CSF analysis
What is the tx for TIA if atherosclerotic?
If Embolic?
If atherosclerotic: Start antiplatelet (ASA, or ASA+ clopidogrel (Plavix) common) + statin
- Surgical approach: carotid endarterectomy, possibly ballooning/stenting
- Prevention: control DM, HTN, HLD, smoking cessation
If embolic: start anticoagulation (heparin, warfarin, Factor X inhibitors, etc)
Describe the basic pathophysiology of intracranial hemorrhage, both deep and superficial.
- Deep hemorrhage: from small vessel, (lenticulostriate) rupture due to HTN (remember cocaine can cause transient cerebral HTN too)
- Superficial hemorrhage: from head trauma, possibly CT disorders
Blood -> Increased ICP -> Severe HA, LOC or impaired consciousness, focal neuro deficits
Both deep and superficial ICH can be compounded if patient is:
Taking anticoagulation meds
What is the general clinical presentation of ICH?
- What additionally might you see w/ deep? Superficial?
HA, LOC, focal neurodeficits
- Deep hemorrhage: basal ganglia or thalamic lesions so movement or sensory disorders
- Superficial: depends, sx as previously mentioned in TIA
What is the w/u for ICH?
CT non contrast looking for bright blood!!!, others CTA, MRI/MRA, CBC/CMP, check INR
What is the tx for ICH?
Manage underlying bleeding disorder if any, FFP and coag factors in some cases, neurosurg for coil/clip placement
What types of seizures does phenytoin (Dilantin) treat?
Complex partial seizures
What types of seizures does carbamazepine (Tegretol) treat?
Recall, what additional thing can it be used for?
Complex or simple partial seizures
also trigeminal neuralgia
What types of seizures does lamotrigine (Lamictal) treat?
Recall, what additional thing can it be used for?
Most seizures (generalized tonic-clonic, absence…)
also BPD
What types of seizures does valproate (Depakote) treat?
Recall, what additional thing can it be used for?
Most seizures (generalized tonic-clonic, absence…)
also BPD
What types of seizures does oxcarbazepine treat?
Simple or complex partial seizures
What types of seizures does levetiracetam (Keppra) treat?
Most seizures
What types of seizures does ethosuximide (Zarontin) treat?
Absence
What are some SE’s of anticonvulsants? (we will go into more detail, just read)
Anticonvulsants may cause confusion, somnolence and ataxia at high serum levels and teratogenicity at minimal serum levels.
What AED’s (anti-epileptic drugs) cause confusion/drowsiness/dizziness?
Phenytoin, carbamazepine, lamotrigine, valproate, oxcarbazepine, levetiracetam (ALL OF THEM)
What are the teratogenic effects of:
- Valproate (Depakote)?
- Lamotrigine (Lamictol) and carbamazepine (Tegretol)?
- Phenytoin (Dilantin)?
- Valproate: NTDs
- Lamotrigine and carbamazepine: oral/facial clefts
- Phenytoin: fetal hydrantoin syndrome: minor dysmorphic craniofacial features and limb defects including hypoplastic nails and distal phalanges
Describe this protocol for treating generalized status epilepticus.
First give lorazepam (Ativan) 0.1 mg/kg (4-8 mg) as an IV bolus, repeatable in 5-10 minutes if needed, followed by loading with either fosphenytoin 20 phenytoin equivalents (PE)/kg IV, no faster than 150 mg/min, or phenytoin 20 mg/kg IV, given in saline no faster than 50 mg/min.
(Give benzo, then if needed give AED)
What are the indications for an emergency LP?
List some additional, less emergent indications.
- Meningitis
- Encephalitis
- SAH (if no blood is detected by CT scan in the latter)
Also for:
- Demyelinating inflammatory disease
- Nl pressure hydrocephalus (“W/W/W”)
- Pseudotumor cerebri (AKA idiopathic intracranial HTN)
What are the contraindications for emergent LP?
- Increased ICP!!! (Signs like papilledema, LOC, focal neuro deficits, asymmetry/shifts on CT) b/c of risk of brain herniation
- Coagulopathy (INR > 1.5 or platelets < 50,000, 6hrs from last heparin, 5 days from last clopidogrel).
- Spinal cord trauma
- Cardiorespiratory compromise
- Overlying skin lesion/infx
Explain how CSF levels of WBCs, protein, and glucose are altered in the following types of meningitis:
- Bacterial
- Viral
- Tuberculosis
- Fungus
- Bacterial: WBCs: 500-1000 (PMNs), ^ protein, v glucose
- Viral: WBCs: < 500 (lympho’s), v/nl protein, nl glucose
- Tuberculosis: < 500 (lympho’s), v protein, ^ glucose
- Fungus: < 500 (lympho’s), v protein, ^ glucose
What type of organism usually causes encephalitis?
In encephalitis, the LP is similar to which type of meningitis infection? (state WBCs, protein, glucose)
Usually viral
- Viral: WBCs: < 500 (lympho’s), v/nl protein, nl glucose
When would you do a low-volume LP for assessing SAH?
What would the fluid look like if positive?
If CT came back inconclusive
- Xanthochromic CSF w/SAME # RBCs in tubes 1 and 4
What is a “traumatic tap” on LP?
How would the result differ from that of a positive SAH LP?
A “traumatic tap” occurs if the needle inadvertently has entered an epidural vein during insertion.
- Traumatic tap will NOT be xanthochromic, and # of RBC’s will drop from tube 1 to 4
How do you treat impaired consciousness due to hypoglycemia?
Give sugar
How do you treat impaired consciousness due to hypothermia?
Rewarming (externally + trunk first, if necessary warm intraperitoneal lavage)
How do you treat impaired consciousness due to narcotics?
Naloxone (Narcan)
How do you treat impaired consciousness due to benzos?
Flumazenil (Romazicon) is controversial, supportive care is standard of care
Describe how IV ______________ can reduce edema or herniation from certain cerebral lesions (tumor, abscess or encephalitis) or spinal cord lesions (metastatic cord compression, myelitis), but primary tx directed at the underlying lesion must soon follow.
Dexamethasone
As described above, IV dex can temporarily reduce the edema surrounding tumors/abscess by suppressing the inflammatory response system
S/s of herpes encephalitis?
Aphasia, behavior change, memory change
How is herpes encephalitis dx’d?
MRI: bilateral/asymmetric involvement of frontal + temporal lobes